MAYTRONICS DL2019 Dolphin Advantage Robotic Inground Pool Cleaner 9999301 Factory Refurbished MAYTRONICS DL2019 Dolphin Advantage Robotic Inground Swimming Pool Cleaner Recommended for Pools up to 20' x 40' Scrubs, brushes, vacuums and filters the entire pool, floor walls and water line in just 3 hours. Large ultra fine filter bag collects dirt, debris and even dust particles. Advanced self-learning scanning programme, optimizing pool coverage.